The distinctive brightly coloured orange tiles of Rosenthaler Platz make it one of the most striking and iconic U-Bahn stations in the city – but there is more to these tiles than meets the eye. They’re actually glazed with uranium.
Take a geiger counter to these tiles, and it immediately begins to click and whirr
As you can see on this post on the social media site mastodon – when you take a geiger counter to these tiles, it immediately begins to click and whirr as a distinct increase in the amount of radiation is detected from the uranium’s ever present decay chain.
So, should you worry? Well, the truth is, no. To be honest, the tiles are probably the least dangerous thing in the station. We spoke with @gigabecquerel and he said that, while he wouldn’t lick the tiles, that wasn’t due to concerns about radiation but rather for the same reason you wouldn’t want to lick anything in an U-Bahn station…
In 2010, radioactive waste was discovered beneath the asphalt on Stargarder Strasse in Prenzlauer Berg
Back when Rosenthaler Platz station was built in 1930, an estimated 25% of all housing used some amount of uranium tiling. Uranium was a waste product but, when used in chemistry, it produced remarkable colours for glazing: vibrant reds, oranges, greens and blues. Uranium tiling has been largely discontinued today, but as @gigabecquerel pointed out to us, this same chemistry continues in glassware where alternative methods to create the same striking colours have not yet been found.
So are there any radioactive materials lying around the city? It’s possible. After all, in 2010, radioactive waste was discovered beneath the asphalt on Stargarder Strasse in Prenzlauer Berg. On that occasion, a small amount of Caesium 137, a radioactive product formed by nuclear fission and used in medical radiotherapy was accidentally discovered by the German Red Cross on a test drive which happened to be carrying a detection device. The material was dug up and disposed of, but even then the risk was relatively low. A person would have to have stood on the same spot for 50 hours for the radioactivity to become harmful.